Where to place the Muratic Acid injector?

[thegizzard]

My equipment was delivered yesterday and while the PB is here I would like them to setup my acid pump. My heater is not installed yet so I am not sure where it is going. Can you advise where the MA should be injected into the system? I have seen different advice here. Should it go before or after the SWCG?

 

[e_sully]

Just had this exact discussion recently. My read of the consensus is that it probably doesn't matter much. I put it after as I have a check valve after the SWCG and if the injector goes berserk, this will protect the SWCG from getting flooded with acid.

Consensus on acid injection - before SWCG or after?

Installing an acid injection system (Hayward AQL-CHEM4-ACID but without the Hayward control, just manual dosing using schedule on Aqualink). Will be using 1:4 diluted 31.45% acid (so about 8%). Searching through the forum, I see the opinions over the years have varied. Some frequent posters...

www.troublefreepool.com

 

[thegizzard]

Thank you. I see that discussion now. I will review that thread.

 

[BowserB]

Personal opinion here. Pentair cautions about pH being too low as shortening the life of the cell. I don't put anything in skimmers, would never pour muriatic acid into a skimmer, and generally don't want anything going through any of the pool equipment with a concentration of any chemical higher than the pool generally. Of course, it's unavoidable that downstream of the SWCG will be high in chlorine, but that's unavoidable. My SWCG is the last thing before returning to the pool, and there is a check valve just before the SWCG. If I were going to do acid injection (and I might one day, as it seems like hauling and pouring acid has taken the place of hauling and pouring chlorine since "upgrading" to SWCG), I would use a low concentrate and absolutely downstream of any other equipment.

 

[Diggy77]

I installed a Hayward sense and dispense years back. Intake of the acid pump was placed just before the pool pump, output of the acid pump was placed just after the salt cell. All done per manufacturer instructions. I would assume the manufacturer would have some wording and diagrams on this. Might be wise to follow them in case of warranty issue.

The system I installed seemed to work well with no ill effects on the equipment. This was a weekly service customer, so we were able to monitor the system closely.